A. Stadlen: "Nabokov's account of the "identical twin" "abysses"...may be phenomenologically true to the particular defective and distorted experience of the young "chronophobiac" who is frightened by seeing film of a few weeks before his birth when, supposedly, he did not "exist". But it is certainly not true to my experience.... Nabokov's description ...as inaccurate as Henry James's description of the lighted "tip" of a cigar ...seemed to Nabokov.//Heidegger in ...Sein und Zeit (1927) replied that birth and death were not a symmetric pair .."

JM: An interesting observation concerning the chronophobiac's "identical twin...abysses" when these are set close to Heidegger's reply in "Being and Time". 
Van Veen's own musings recreate such terrors when he considers it impossible to confront a twinned "second nothing": "...we can speak of past time, and in a vaguer, but familiar sense, of future time, but we simply cannot expect a second nothing, a second void, a second blank. Oblivion is a one-night performance; we have been to it once, there will be no repeat. We must face therefore the possibility of some prolonged form of disorganized consciousness." Van is captivated by conscious experience, like his insomniac creator, in which there's obviously no place for a Freudian "unconscious."